What is GPG?
Bearing journal dimensions are critical. For maximum life and spindle performance worn journals must be restored to manufacturer’s specifications. If your spindle has worn journals, out of tolerance shaft taper or other worn dimensional critical areas these may require “Grind-Plate-Grind”. Worn areas are first ground to a uniform undersize dimension. This is the first “Grind” often called a “green grind”. The part is then hard plated to an oversize dimension. This is the “Plate”. After plating, the part is re-ground to the exact nominal dimension; the final “Grind” of GPG.
